Friday, April 06, 2007

CAP-XX Flash Power

Mobile Handset Design Line has CAP-XX article on LED flash power in camera phones. The proposal is to use 0.55F super-capacitors to provide high current pulse for LED flash. There is a table comparing various light sources in different camera-phones vs. super-capacitor options:

Source Storage Capacitor Distance (m) Peak Light Power (lux) Exposure Time (msecs) Light Energy (lux.secs)
Xenon, SonyEricsson K750 60μF 1 370,000 <1> 37.0
Xenon, SonyEricsson K800 2 x 14μF 1 203,000 <1> 16.0
Xenon, Gigabyte cell phone 15μF 1 139,000 <1> 6.2
4 x LEDs @ 1A each 0.55F 1 708 17 10.8
33 21.9
67 43.7
2 x LEDs @ 1A each 0.55F 1 349 17 5.3
33 10.9
67 21.4
Nokia N73 LED Flash NA 1 20.0 90 1.71
Xenon, SonyEricsson K750 60μF 2 97,000 <1> 9.5
Xenon, SonyEricsson K800 2 x 14μF 2 53,000 <1> 4.2
Xenon, Gigabyte cell phone 15μF 2 36,000 <1> 1.7
4 x LEDs @ 1A each 0.55F 2 175 17 2.7
33 5.4
67 10.8
2 x LEDs @ 1A each 0.55F 2 86 17 1.3
33 2.7
67 5.3
Nokia N73 LED Flash NA 2 5.0 90 0.43

No comments:

Post a Comment

All comments are moderated to avoid spam and personal attacks.